Apparatus for transferring liquids

ABSTRACT

An apparatus for transferring a liquid via a liquid conducting means from a donor receptacle to a receiving receptacle, which includes cleaning and drying means for the liquid conducting means.

[151 3,677,091 [451 July 18, 1972 United States Patent Guigan APPARATUSFOR TRANSFERRING LIQUIDS [72] Inventor:

Jean Gulgan, Paris, France Hoffman-La Roche Inc.,

Nutley, NJ.

[73] Assignee:

Primary Examiner-S. Clement Swisher Attorney-Samuel I... Welt, Jon S.Saxe, Bernard S. Leon, William G. Isgro, Margaret C. Bogosian and JacobFrank 0 7 9 l 7 .w W 7 A6 Q N 1 0. MP FA .4H 22 ....73/423 A, 23/253ABSTRACT G0ln 1/14 73/423 A 421 B; 356/244, 246; An apparatus fortransferring a liquid via a liquid conducting 52 US. 511 InLCl.

[58] field of Search means from a donor receptacle to a receivingreceptacle, which includes cleaning and drying means for the liquidconducting means.

14Clalrm,5Drawlngl1gures PATENTEU JUL 1 8 I972 SHEET 3 BF 3 FIG. 3

APPARATUS FOR TRANSFERRING LIQUIDS BRIEF SUMMARY OF THE INVENTION Theinvention relates to an apparatus which comprises a support means, acarrying member mounted on said support means for vertical andhorizontal movement, a plurality of liquid conducting means, preferablyhollow, double pronged needles, secured to said carrying member and aplurality of cleaning and drying means disposed on said support meansand adapted to receive the liquid conducting means, whereby the lattercan be cleaned and dried. In operation, the liquid conducting meanscooperates in the transfer of a liquid substance from a donor containerto a receiving container and then moves upwardly, horizontally and thendownwardly into the cleaning receptacle, where it is cleaned by liquidmeans. It then again moves upwardly, horizontally and ten downwardlythrough predetermined distancesiinto the drying means, where anyresidual liquid substance is removed by drying. Preferably, thesubstance is a sample taken from a human, and the sample is destined foranalysis for diagnostically significant features.

DETAILED DESCRIPTION OF THE INVENTION It is known to cause the transferof a liquid by means of a hollow, double pronged needle, one branch ofwhich dips into a donor container and the other branch of which dipsinto a receiving container, under the influence of a compressed gasintroduced into the donor container by another needle. In manyinstances, in such an operation, the hollow, double pronged needletraversed by the liquid is contaminated so that it is important toeffect a careful cleaning of said needle prior to its re-use. This isparticularly true in the case of medical analyses where microbiologicalcontamination from one sample to the next must be avoided. The aim ofthe invention is an apparatus whereby this cleaning, drying andtransferring is accomplished automatically.

The invention has for its object an apparatus for transferring liquidsamples by liquid conducting means, which is put into communicationsimultaneously with the donor container and a receiving container. Ahollow needle directs a pressure means into the donor container, wherebythe interior of the donor container is put under pressure and includingcleaning and drying means for said liquid conducting means. Theapparatus of the invention is characterized by the fact that itincludes: (a) a support means which may comprise a base and a firsthorizontal member connected to the base by vertical mountings; (b) aplurality of hollow, double pronged needles, preferably n in number,carried by a second horizontal member and positioned on said secondmember equadistant radially from the vertical axis thereof, the saidsecond horizontal member being operatively disposed on the supportmeans, for example, between the said base and first horizontal member,whereby relative horizontal and vertical movement thereof is permitted;(c) a plurality of cleaning and drying vessels or troughs, for theliquid conducting means equal, preferably, in number to at most n-l,said vessels or troughs being disposed on the base of the said supportmeans in the path of vertical movement of the liquid conducting meanseffected concurrently with the vertical movement of the said secondmember; (d) a hollow conducting member connected to a source of positivepressure and resiliently mounted in relation to said support means on aguiding member for movement in a downward vertical direction uponcoaction with said second horizontal member and disposed opposite adouble hollow needle which is not in vertical communication with acleaning or drying vessel or trough; (e) a first actuating meansoperatively connected to said second horizontal member and energized toeffect rotational movement of said second member relative to saidsupport means in successive rotatory movements with an angle equal to 21r/n; and (f) a second actuating means also operatively connected tosaid second horizontal member and energizable to effect movement of saidsecond member in a vertical direction relative to said support means.

In a preferred embodiment,

the movement in a vertical direction of said second horizontal member isguided by means oflongitudinal projections integral with, and extendingfrom the said second horizontal member, said projections being slidablyreceived in longitudinal grooves of the vertical mountings disposed onthe base of the supporting means, these grooves opening laterally at theupper extremity of the mountings thereby removably receiving saidprojections so that they can move laterally;

the said rotary movement with an angle equal to 2 rr/n of the saidsecond horizontal member about its vertical axis may be effected by amotor of the step-by-step type fixed on said support means, the axis ofthe said motor passing through the axis of the said second horizontalmember and the latter being connected in rotation but free in verticalmovement;

the means for moving the said second horizontal member in verticaldirection include a screw-jack or an electromag net acting thereon; themeans for moving the hollow conducting member consist, in descent, inthe action of the second horizontal member on a small plate supportingthe said hollow needle and, in rising, in the action of a return spring,disposed below said small plate; the cleaning vessels or troughs includetwo cavities into each of which there dips one branch of one, doubleneedle; the first cavity being provided with an inlet and an outletconduit for compressed gas; and with an inlet conduit for a cleaningliquid which is renewed and maintained at a substantially constantlevel, the second cavity being provided with a conduit for evacuatingcleaning liquid transferred thereto by the double needle;

the said drying vessels or troughs include two cavities into each ofwhich dips a branch of a double needle; a first cavity being providedwith an inlet conduit for hot gas; the second cavity being provided withan escape conduit for the said gas after its transfer through the saidneedle.

In a variant embodiment, a level detector, connected to the platesupporting the hollow pressure conducting needle, stops the descent ofthe second horizontal member when the free surface of the liquidcontained in the donor container is detected; the positioning of thesaid detector relative to the plate permits predetermination of thequantity of liquid to be transferred.

The present invention will be better understood by consideration of theexemplary embodiment given hereinafter with reference to theaccompanying drawings wherein:

FIG. 1 is an embodiment of the apparatus of the invention in perspectiveview;

FIG. 2 is an exploded perspective view of the apparatus corresponding toFIG 1;

FIG. 3 is a longitudinal sectional view of an embodiment of the donorand receiving containers;

FIG. 4 is a longitudinal sectional view of an embodiment of the cleaningmeans;

FIG. 5 is a longitudinal sectional view of an embodiment of the dryingmeans.

Referring to the drawings, more particularly, FIG. 1, the apparatuscomprises:

The fixed support comprises a base member 1 and a first horizontalmember 2. The first horizontal member 2 is provided with an openingabout its central vertical axis and comprises five radially extendingarms positioned about the opening. Four upstanding mountings 3 arefixedly secured to the base member 1 at one end thereof and to thehorizontal member 2 at the other end of the mountings. The mountings arepreferably annular in configuration and are provided at their upper endswith a semi-circular reduced portion 5. Mountings 3 also have formedalong the length of the nonreduced portion thereof, a longitudinallyextending groove 4.

A second horizontal member 6 supports five sets of hollow, doublepronged liquid conducting means on five radially extending arms. Saidliquid conducting means comprises five double pronged hollow needles 7.Member 6 is provided with longitudinal projections; namely, lugs 8,which are slidably and guidably received in grooves 4. Member 6 has acentral opening in which is fixedly received, a hollow axle 9. Axle 9 isconnected on one end with the piston of an actuator 10. The actuator 10may comprise a screw-jack such as a pneumatic jack operated byrapid-action electromatic valves, an electrohydraulic jack or any devicefor transmitting the required movements. The other end of axle 9receives interiorly, the axle or shaft 11 of a motor 12. Shaft 11 isrectangular in configuration and is received in a corresponding openingin the hollow axle 9. Thus, relative rotational movement about thevertical axis of axle 9 and shaft 11 is precluded but relative slidingmovement along the vertical axis thereof is permitted.

The apparatus also comprises cleaning and drying troughs 13 disposeddirectly opposite to four of the hollow needles 7 when in operativeposition.

A single pronged hollow needle 14 is fixedly secured to a plate 15. Oneend of needle 14 is connected to a source of gas or air under pressurethrough conduit 62. The plate 15 is mounted on a mount 16 for verticalmovement. Mount 16 is fixed to a projection 17, formed integrally withmember 2 and extending downwardly from member 2. Mount carries a stop18. A biasing means such as helical spring 22 is disposed about mount 16between the underside of plate 15 and the upper surface of stop 18,whereby plate 15 is biased in an upward direction under the influence ofspring 22. Plate 15 has a downwardly extending leg 60. To the free endof leg 60, detector 23 is fixed. Movement of plate 15 is limited byprojection 17 and stop 18.

A donor container 20 and a receiving container 21 are removably fedbelow needle 7 by any suitable means. In operation, containers 20 and 21are positioned on the apparatus so that the branch of the needle 7adjacent to needle 14 is above donor compartment 20 and the other branchof needle 7 is above receiving compartment 21. The actuator 10 is thenenergized by any suitable means causing the second horizontal member 6to descend. One branch of needle 7 penetrates donor container 20, andthe other branch penetrates container 21. The other needles 7 asdescribed hereinafter, enter a cleaning trough or a drying trough. Thesecond horizontal member or needle carrying member 6 engages plate 15 asshown in FIG. 3, as it moves downwardly causing needle 14 to enter thedonor compartment 20, while also causing compression of spring 22.

As FIG. 3 indicates, needle 14 and one branch of a double needle 7enters the donor container 20 and the other branch of the last-mentioneddouble needle enters the receiving container-21. The needle 14 isconnected to a source of compressed gas or air through conduit 62 asindicated above. The liquid contained in the donor container 20 isdriven into the container 21 via hollow needle 7. The optical leveldetector 23 disposed below the small plate 15 additionally permits, bycontrolling the drive of the piston 10, the predetermination of thevolume of liquid substance to be transferred. To accomplish this latterpurpose, it is sufiicient to adjust the difference of level between thedetector 23 and the extremity of the double needle; as the detectorstops the descent of the second horizontal member 6 when it detects theinitial level of the liquid in the container 20, then the volumetransferred is equal to that comprised between this initial level andthe extremity of the double needle.

Simultaneously, with the transfer operation carried out by needle 7 toadjacent container 21, the four other needles are cleaned and dried asindicated in FIGS. 4 and 5, respectively, and described hereinafter.

Referring to the drawings, more particularly to FIG. 4, one

, of the needles dip into cleaning trough 47, including two cavities 40and 41. Cavity 40 contains a cleaning liquid 45 which can be replacedand maintained at a substantially constant level by conduits 42 and 43.Conduit 44 permits the liquid contained in cavity 40 to be put underpressure, whereby the liquid contained therein circulates through theinterior of the dollow, double pronged needle 7. The liquid transferredis removed from cavity 41 via conduit 46.

Referring to the drawings, more particularly to FIG. 5, another set ofhollow, double pronged needles 7, clips into a drying trough 54analogous to a cleaning trough 47 except for the liquid feed circuit.Conduit 50 introduces a hot gas into cavity 51, this circulates throughthe interior of the double needle 7 and escapes from cavity 52 byconduit 53.

The movement of a set of hollow, double pronged needles from oneposition to the next is effected by means of motor 12. When the secondhorizontal member 6 is in its uppermost position, the projections 8 aresituated adjacent the semi-circularly reduced positions 5 free fromgrooves 4. The motor 12 which is operatively connected to plate 6 viaaxles 9 and 11 cause the flat carrying member 6 to rotate to the nextoperative portion. Each projection 8 is then adjacent a groove 4, andeach needle 7 is above either a sample container, a cleaning trough, ora drying trough. It should be evident that a cleaned and dried needle 7is above the donor container and the needle 7 which last transferred thesample is above a cleaning trough.

It is to be noted that the relative number of cleaning and dryingtroughs can be two or more depending upon the result desired. Likewise,the total number of positions can be modified by changing in the samefashion the number of the corresponding elements such as mountings,needles, and the like.

The apparatus described herein can be particularly useful in conjunctionwith the automatic transfer apparatus described in U.S. Pat. ApplicationSer. No. 793,498, filed Jan. 23, 1969 in the name of Robert Laucournet.

In a more detailed operation, when a control signal occurs, the actuator10 pushes the needles through plugs 70 positioned in all of thecontainers, i.e., the donor receiving container; the cleaning trough orthe drying troughs, into the position illustrated in FIG. 1. One branchof the needle 7 enters the donor container 21 and contacts the liquidsubstance contained therein. The needle 14 arrives at a position abovethe surface of the liquid sample. The opening of the needle 14 permitscompressed air to enter the free portion of the donor container 20without disturbing the surface of the liquid. The pressure establishedin the free portion pushes the liquid in the donor container 20 into theopen end of needle 7. When the designated amount of liquid istransferred from the donor container 20 to the receiving container 21,the actuator 10 causes upward movement of plate 6, downward movementbeing stopped when the detector 23 senses the upper surface of thesample. The plate 6 and the needles 7 associated therewith, movesupwardly until the lugs 8 are no longer in communication with thegrooves 4. Thereafter, the motor 12 rotates about its vertical axiscausing concurrent rotation of the plate 6. Rotation is continued untilthe device is in a position whereby the needles can penetrate the plugsor resiliently deformable covers 70 contained in the receptacle disposednext adjacent the container, cleaning or drying trough where they werelast positioned. In this way, there can be provided a means fortransmitting an aliquot of sample into a system which is to analyze itfor diagnostically significant factors. For example, the apparatusdefined herein can be utilized with a system described in applicationSer. No. 793,498, referred to above. In the system, a compartmentcontained upon a film strip is charged with a material to be analyzedfor diagnostically significant factors, such as the presence of urea inblood and the like. The apparatus herein defined is also well suited forproviding a transfer of liquid into such compartment. Therefore, in theembodiment, in lieu of compartment 21, a receiving compartment containedon a film strip can be utilized.

I claim:

1. An apparatus for transferring a liquid substance from a donorcontainer to a receiving container via a liquid conducting meanscomprising a support means, a carrying member mounted on said supportmeans for relative rotational movement about its vertical axis through a360 angle and for relative vertical movement along its vertical axis, aplurality of said liquid conducting means secured to said carryingmember at positions radial to the vertical axis of said carrying member,said liquid conducting means extending downwardly from said carryingmember, and cleaning and drying means for the said liquid conductingmeans, including at least one cleaning trough and one drying trough,said troughs being disposed on the support means in the path of relativevertical movement of said liquid conducting means with respect to saidtroughs.

2. An apparatus as in claim 1 wherein the liquid conducting meanscomprises hollow, double pronged needles extending downwardly from saidcarrying member.

3. An apparatus as in claim 2 above wherein there is associated with theliquid conducting means, a hollow conducting member connected to apressure supplying means whereby the liquid substance to be transferredis transferred through the hollow, double pronged needles under theinfluence of the pressure provided by the pressure supplying means.

4. An apparatus for transferring a liquid substance from a donorcontainer to a receiving container comprising a support means, acarrying member mounted on said support means for relative rotationalmovement about its vertical axis and for relative vertical movementalong its vertical axis, a plurality of liquid conducting means, n innumber, carried by said carrying member and fixed to the carrying memberat positions equadistant radially from the vertical axis of the carryingmember, said liquid conducting means extending downwardly from saidcarrying member, cleaning and drying means for the liquid conductingmeans, including at least one cleaning trough and one drying trough,said troughs being disposed on the support means in the path of relativevertical movement of the liquid conducting means with respect to thesaid trough, a pressure means supplying member comprising a guide fixedagainst movement relative to the support means, and a hollow conductingmember operatively connected to the guide for vertical movement relativethereto, said hollow conducting member being disposed adjacent a liquidconducting means which liquid conducting means does not have a troughdisposed in the path of relative vertical movement thereof, a firstactuating means operatively connected to said carrying member and beingenergizable to effect rotational movement of said carrying member aboutits vertical axis relative to said support means in equal rotaryincrements, a second actuating means also operatively connected to saidcarrying member and being energizable to effect movement of saidcarrying member in a vertical direction relative to said support meansand means for effecting relative vertical movement of the hollowconducting member with respect to said guide.

5. Apparatus as defined in claim 4 wherein the support means comprises abase, an upper member positioned above the base and vertical mountingmeans secured on the lower portion thereof to the base and on the upperportion thereof to the upper member whereby relative movement of thebase and the upper member is precluded.

6. Apparatus as defined in claim 5 in which said carrying member isadapted to move vertically in response to actuation of said secondactuation means, and said mounting member and said carrying member areprovided with cooperating means for guiding said carrying member alongits path of vertical movement.

7. Apparatus as defined in claim 6 in which said cooperating meansincludes a projection formed at the periphery of said carrying member,and a vertical groove formed along a portion of the length of a verticalmounting means, said projection adapted to be slidably received in saidvertical groove during the vertical movement of said carrying member.

8. An apparatus as in claim 7 in which the vertical mounting meansinclude a reduced portion adjacent said upper member and a non-reducedportion containing said vertical groove, said non-reduced portion beingdisposed in the path of horizontal movement of said projection, saidreduced portion being out of the path of horizontal movement of saidprojection, whereby when said projection is received in said groove,vertical but not horizontal movement of the carrying member ispermitted, but when said projection is received in the space defined bythe reduced portion, vertical and horizontal move ment of the carryingmember is permitted.

9. Apparatus for transferring a liquid substance in accordance withclaim 5, in which the said horizontal movement of the carrying member isthrough an angle equal to 2 1r/n and the first actuating means is amotor of the step-by-step type secured to said base, the vertical axisof an axle driven by said motor being coincident with the vertical axisof the carrying member, said axle being operatively connected to saidcarrying member for relative vertical movement and for conjointrotational movement.

10. Apparatus for transferring a liquid substance in accordance withclaim 4, in which said second actuating means includes a screw-jack oran electromagnet acting thereon.

11. Apparatus for transferring a liquid substance in accordance withclaim 4, in which the said pressure means sup plying member includes asupporting plate slidably mounted on said guide for movement in avertical direction, said hollow conducting member being secured to saidsupporting plate and extending downwardly therefrom, a biasing meansmounted on said guide and biasing said supporting plate in an upwarddirection, said supporting plate being disposed in the path of verticalmovement of the carrying member whereby vertical movement of thecarrying member in a downward direction effects vertical movement of thesupporting plate in a corresponding direction against the bias of saidbiasing means.

12. Apparatus for transferring liquid substances in accordance withclaim 11, in which a level detector is connected to the said supportingplate for vertical movement therewith, said detector being adapted tosense the upper level of the liquid substance to be transferred and tocause a signal to be sent to the second actuating means when such levelis detected whereby downward vertical movement of said carrying memberceases, the position of the detector relative to the said supportingplate predetermines the quantity of liquid substance to be transferred.

13. Apparatus for transferring liquid substances in accordance withclaim 4, in which the said liquid conducting means comprises a doublebranched hollow needle and the said cleaning troughs include twocavities into each of which dips one branch of said double needle, thewalls of one of said cavities being provided with openings adapted toreceive inlet and outley cleaning liquid conduits, whereby a cleaningliquid can be provided, renewed and maintained at a substantiallyconstant level, said one cavity also being provided with an openingadapted to receive a compressed gas conduit; and the walls of the othercavity being provided with an opening adapted to receive an evacuatingconduit whereby the cleaning liquid transferred into said other cavityby the said hollow needle can be evacuated.

14. Apparatus for transferring liquid substances in accordance withclaim 4, in which the said liquid conducting means comprises a doublebranched, hollow needle, said drying troughs include two cavities, intoeach of which dips one branch of said double needle, one of saidcavities having secured to the wall defining this cavity, an inletconduit for hot gas and the wall defining the other of said cavity beingprovided with an escape conduit for the said gas after its transferthrough the said hollow needle.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTWN Patent No.5,677,091 Dated July 18, 1972 lnvent fl Jean Guiggn It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Cover page, Column 1, following "[21] Appl. No. 67,519" and before "[52]U.S. c1. .....'('3/ 23A, 23/253" should read:

[30] Foreign Application Priority Data France September 4, 1969 No.6930205 Signed and sealed this 3rd day of April i973.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents F ORM PO-1050 0-69) USCOMM-DC 60376-P6Q U.5. GOVERNMENTPRINTING OFFICE 1989 O-36S-334

1. An apparatus for transferring a liquid substance from a donorcontainer to a receiving container via a liquid conducting meanscomprising a support means, a carrying member mounted on said supportmeans for relative rotational movement about its vertical axis through a360* angle and for relative vertical movement along its vertical axis, aplurality of said liquid conducting means secured to said carryingmember at positions radial to the vertical axis of said carrying member,said liquid conducting means extending downwardly from said carryingmember, and cleaning and drying means for the said liquid conductingmeans, including at least one cleaning trough and one drying trough,said troughs being disposed on the support means in the path of relativevertical movement of said liquid conducting means with respect to saidtroughs.
 2. An apparatus as in claim 1 wherein the liquid conductingmeans comprises hollow, double pronged needles extending downwardly fromsaid carrying member.
 3. An apparatus as in claim 2 above wherein thereis associated with the liquid conducting means, a hollow conductingmember connected to a pressure supplying means whereby the liquidsubstance to be transferred is transferred through the hollow, doublepronged needles under the influence of the pressure provided by thepressure supplying means.
 4. An apparatus for transferring a liquidsubstance from a donor container to a receiving container comprising asupport means, a carrying member mounted on said support means forrelative rotational movement about its vertical axis and for relativevertical movement along its vertical axis, a plurality of liquidconducting means, n in number, carried by said carrying member and fixedto the carrying member at positions equadistant radially from thevertical axis of the carrying member, said liquid conducting meansextending downwardly from said carrying member, cleaning and dryingmeans for the liquid conducting means, including at least one cleaningtrough and one drying trough, said troughs being disposed on the supportmeans in the path of relative vertical movement of the liquid conductingmeans with respect to the said trough, a pressure means supplying membercomprising a guide fixed against movement relative to the support means,and a hollow conducting member operatively connected to the guide forvertical movement relative thereto, said hollow conducting member beingdisposed adjacent a liquid conducting means which liquid conductingmeans does not have a trough disposed in the path of relative verticalmovement thereof, a first actuating means operatively connected to saidcarrying member and being energizable to effect rotational movement ofsaid carrying member about its vertical axis relative to said supportmeans in equal rotary increments, a second actuating means alsooperatively connected to said carrying member and being energizable toeffect movement of said carrying member in a vertical direction relativeto said support means and means for effecting relative vertical movemEntof the hollow conducting member with respect to said guide.
 5. Apparatusas defined in claim 4 wherein the support means comprises a base, anupper member positioned above the base and vertical mounting meanssecured on the lower portion thereof to the base and on the upperportion thereof to the upper member whereby relative movement of thebase and the upper member is precluded.
 6. Apparatus as defined in claim5 in which said carrying member is adapted to move vertically inresponse to actuation of said second actuation means, and said mountingmember and said carrying member are provided with cooperating means forguiding said carrying member along its path of vertical movement. 7.Apparatus as defined in claim 6 in which said cooperating means includesa projection formed at the periphery of said carrying member, and avertical groove formed along a portion of the length of a verticalmounting means, said projection adapted to be slidably received in saidvertical groove during the vertical movement of said carrying member. 8.An apparatus as in claim 7 in which the vertical mounting means includea reduced portion adjacent said upper member and a non-reduced portioncontaining said vertical groove, said non-reduced portion being disposedin the path of horizontal movement of said projection, said reducedportion being out of the path of horizontal movement of said projection,whereby when said projection is received in said groove, vertical butnot horizontal movement of the carrying member is permitted, but whensaid projection is received in the space defined by the reduced portion,vertical and horizontal movement of the carrying member is permitted. 9.Apparatus for transferring a liquid substance in accordance with claim5, in which the said horizontal movement of the carrying member isthrough an angle equal to 2 pi /n and the first actuating means is amotor of the step-by-step type secured to said base, the vertical axisof an axle driven by said motor being coincident with the vertical axisof the carrying member, said axle being operatively connected to saidcarrying member for relative vertical movement and for conjointrotational movement.
 10. Apparatus for transferring a liquid substancein accordance with claim 4, in which said second actuating meansincludes a screw-jack or an electromagnet acting thereon.
 11. Apparatusfor transferring a liquid substance in accordance with claim 4, in whichthe said pressure means supplying member includes a supporting plateslidably mounted on said guide for movement in a vertical direction,said hollow conducting member being secured to said supporting plate andextending downwardly therefrom, a biasing means mounted on said guideand biasing said supporting plate in an upward direction, saidsupporting plate being disposed in the path of vertical movement of thecarrying member whereby vertical movement of the carrying member in adownward direction effects vertical movement of the supporting plate ina corresponding direction against the bias of said biasing means. 12.Apparatus for transferring liquid substances in accordance with claim11, in which a level detector is connected to the said supporting platefor vertical movement therewith, said detector being adapted to sensethe upper level of the liquid substance to be transferred and to cause asignal to be sent to the second actuating means when such level isdetected whereby downward vertical movement of said carrying memberceases, the position of the detector relative to the said supportingplate predetermines the quantity of liquid substance to be transferred.13. Apparatus for transferring liquid substances in accordance withclaim 4, in which the said liquid conducting means comprises a doublebranched hollow needle and the said cleaning troughs include twocavities into each of which dips one branch of said double needle, thewalls of one of said cavities being provided with openings adapted toreceive inlet and oUtley cleaning liquid conduits, whereby a cleaningliquid can be provided, renewed and maintained at a substantiallyconstant level, said one cavity also being provided with an openingadapted to receive a compressed gas conduit; and the walls of the othercavity being provided with an opening adapted to receive an evacuatingconduit whereby the cleaning liquid transferred into said other cavityby the said hollow needle can be evacuated.
 14. Apparatus fortransferring liquid substances in accordance with claim 4, in which thesaid liquid conducting means comprises a double branched, hollow needle,said drying troughs include two cavities, into each of which dips onebranch of said double needle, one of said cavities having secured to thewall defining this cavity, an inlet conduit for hot gas and the walldefining the other of said cavity being provided with an escape conduitfor the said gas after its transfer through the said hollow needle.